Fire extinguisher



A ril 27,1926

R. W. AUSTIN FIRE EXTINGUISHER Filed June 16 Inaurwfov 95% W. mi

@W azgh arr-am uw I Patented Apr. 27, 1926.

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FIRE EXTINGUISHER.

Application filed June 16, 1924. Serial No. 720,147.

To all whom it may concern Be it known that I, RALPH 1V. AUs'rIN, a citizen of the United States, residing at Quincy, in the county of Norfolk and Com monw alth of Massachusetts, have invented certain new and useful Improvements in Fire Extinguishers; and I do hereby declare the following to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to a fire extinguisher, and has for an object to provide a novel and improved fire extinguisher which is capable of operating with maximum efiiciency under relatively high or low temperature conditions and whose efficiency, in addition, is not decreased by exposure to relatively high or low temperatures for long periods of time. 1 i1 IVith this object in View the invention consists in the fire extinguisher hereinafter described and particularly pointed out in the claims at the end of this specification.

The drawing illustrates the preferred embodiment of the invention in vertical section.

In the usual form of fire extinguisher an extinguishing liquid is ejected upon the fire by gas pressure generated by the reaction of a normally isolated carbonate solution with a normally isolated acid solution when the extinguisher is inverted.

In my application, Serial No. 589,355 I have described an extinguisher which is designed to operate with maximum efficiency at extremely low temperatures approaching 40 F. and in which a composition comprising potassium carbonate solution having potassium hydroxide dissolved therein is employed as the basic chemical. The gas pressure is produced by the reaction upon the basic chemical of sulphuric acid of a definite concentration, preferably 74.5% acid by weight. Both the basic chemical and the acid are normally isolated from one another, the acid being maintained in a separate receptacle and arranged to be capable of readily mixing together with the basic chemical upon inversion of the extinguisher. I have found, however, that a tendency exists for the acid to absorb moisture from the air within the extinguisher thus becoming gradually diluted, and as a result the freezing point of the acid solution is gradually raised. In an experimental test exposing an extinguisher containing sulphuric acid of 74.5% acid for three months at a temperature of 120 F., it was found that the concentration of the acid decreased to approximately 61%.

The following table will illustrate the variation of the freezing point with the dilution of the acid.

% H2504 by weight. Freezing point.

74.5 41 F. 73.14 38.9 F. 71.0 -40 F. 61.0 30 F. 57.0 25 F.

In accordance with the present invention I have found that the absorption of moisture by the acid may be advantageously prevented by the use of a sealing liquid Within the ,acid container and which in effect forms a protective film covering the upper surface of the acid. .It is desirable that the sealing liquid should be of an inert material which would not react with either the acid or the base, which would not absorb moisture or which does not contain moisture, which has a specific gravity less than that of the acid, which is non-combustible, which has a low freezing point and a high boilin point. I have found that acetylene tetrach oride possesses the desired properties and qualifications for a most successful sealing liquid.

Referring to the drawing, the fire extinguisher illustrated therein comprises a metal casing 10 preferably of usual construction having an opening 12 therein and a neck 13 threaded and upon which the usual extin guisher cap 14 is screwed. The casing 10 is normally filled with an extinguishing liquid to approximately the level indicated in the drawing. The extinguishing liquid is discharged during the'operation of the extinguisher through a discharge nozzle 15 of usual construction by the gas pressure de- -veloped preferably by the reaction of an acid with a carbonate solution, when the e."- tinguisher is turned into an operative position, or inverted. The carbonate solution and acid may and preferably will be. contained in separate receptacles 16, 18, arranged one within the other, and the car- ,bonate receptacle 16 comprises preferably a metal tube closed at one end 17 and of such diameter as to be capable of insertion into the opening 12 in the extinguisher casing. The metal tube 16 is preferably soldered or otherwise secured to a .neck ring to be supported thereby and the latter is provided with an annular flange 2 2 which rests upon the neck 13 of the extinguisher casing and is removably clamped in such position by the extinguisher cap 14 as illustrated. The neck ring 20 is also provided with a threaded annular rin 25into which a cap 24 is screwed to close t e upper end of the container 16. The cap 24 has threaded into it a cylindrical sleeve 26, which surrounds the stopper 28 of the acid container 18. The acid container 18 is normally closed by the stopper 28, and is supported within the metal tube 16 upon supporting members 30 soldered or otherwise secured to the interior of the metal tube, as will be described. The metal tube 16 and acid bottle 18 are filled with the suitable quantities of carbonate solution and acid respectively, and when the extinguisher is inverted, the acid from the container 18 flows through openings in the sleeve 26 into the inverted upper end of the tube 16 where it mixes with the carbonate, which has also flowed into this end of the tube 16, generating carbon-dioxide gas. Provision is preferably made for conducting this carbon dioxide gas from within the metal container 16 to above the extinguishing liquid in the inverted casing 10, and for this purpose, as herein shown, the metal container 16 is provided with two sets of tubes 36 and 44 respectively. The tubes 44 are extended through the entire length of the metal tube 16 and through the bottom 17 therein, and form direct vpassages for conducting the gas pressure from the chamber or space 38 between the cap 24 and the extinguisher cap 14 to above the extinguishing fluid when the extinguisher is in an inverted position. The metal tubes 36 are preferably arranged to connect the space 38 with that portion of the interior of the metal container 16 above the level of the carbonate solution therein when the extinguisher is in an inverted position, so that the carlpn dioxide gas generated may pass upwardly throughthe carbonate solution and thence downwardly through the tube 36 through the space 38 and thence upwardly through the tubes 44 to above the extinguishing liquid Within the casing 10. The tubes 36 are preferably arranged of such length that in the normal upright position of the extinguisher the ends of the tubes will be located above the normal level of the car bonate solution within the container, so that when the extinguisher is inverted little opportunity is aflorded for any material quantity of the carbonate to pass down into the space 38 between the caps 24 and 14 respectively. If the ends of the tubes 38 are permitted to extend into the carbonate solution, then when the extinguisher is inverted, a substantial quantity of the, carbonate solution will run down into the space 38 so that the small quantity of calcium chloride solution, when the latter is employed in the extinguishing liquid, will react with: the carbonate solution 'to form a precipitate of calcium carbonate which operates to clog up the space 38 and to detract from the successful operation of the extinguisher. The acid container 18 is supported within the metal tube 16 upon a bottle supporting member 30 comprising preferably a spider having arms 50 provided with semi-cylindrical portions 52 upon the ends thereof secured to the conduits 36, 44.

Within the acid container 18 a film or layer 60 of an inert sealing material is provided covering the upper surface of the acid, and comprising preferably acetylene tetrachloride. This sealing film serves to prevent the absorption of moisture by the acid from the air within theextinguisher.

From the description thus far it will be apparent that by means of the present invention an extinguisher is provided capable of withstanding extremely low temperatures in the neighborhood of 40 F., and whose efliciency is unaffected by exposure to such temperatures for long periods of time. In addition, the extinguisher may be successfully exposed to relatively high temperatures such asexist in Warm climates approximating 120 F. without any ill effects upon its operation.

While the preferred embodiment of the invention has been illustrated and described, it will be understood that the invention may .be embodied in other forms within the scope of the following claims.

Having thus described the invention, what is claimed is 1. A fire extinguisher provided with an extinguisher casing, a receptacle within the casing containing a carbonate solution, a second receptacle within the casing containing an acid solution and provided with a body of inert sealing liquid covering the upper surface of the acid.

2. A fire extinguisher provided with an extinguisher casing, a receptacle within the casing containing a carbonate solution, a separate receptacle within the casing containing an acid solution, and a body of acetylene tetrachloride sealing the upper surface of the acid.

3. In a fire extinguisher, gas pressuregenerating chemicals including a normally isolated carbonate solution capable of withstanding low temperatures without freezing, a normally isolated acid solution capable of withstanding low temperatures without freezing, and a body of acetylene tetrachlgride sealing the upper surface of the am 4. A fire extinguisher provided with an extinguisher casing a receptacle in the casing containing a solution of potassium carwithstanding low temperatures Without freezing.

5. In a fire extinguisher, a container, said container having a body of acid and a layer of acetylene tetrachloride sealing the upper surface of the acid.

RALPH V. AUSTIN. 

